The '960 patent describes a novel method of drying a damp or waterlogged room through the use of heated ducting which permits heated air to be recirculated within the room until it reaches a required humidity level or until a given time period has elapsed, whereafter the heated air is exhausted from the room via the ducting. The apparatus for accomplishing this is shown in FIGS. 4 to 7 of the '960 patent and essentially consists of a portable steel trolley supporting a housing and various air inlet and outlet ducts, five in total, for moving heated air around the room being dried in air recirculation mode and, in exhaust mode, removing hot and humid air from the room, to be replaced by ambient air from outside. This arrangement has proven to be very satisfactory in many respects but has some disadvantages, including that the apparatus is quite bulky and therefore cannot be used in confined spaces, such as in crawl spaces below floors or roofs. In addition, being mounted on a trolley the apparatus is quite heavy, weighing over 50 kg and is therefore not suitable for being lifted by a single person without risk of injury.
The present invention is derived in part from the realisation that the movement of heated air around or from a damp room should be possible by means of apparatus that is more user friendly than that described in the '960 patent.